The effect of physical characteristics and field position on the shoulder and elbow injuries of 490 baseball players: confirmation of diagnosis by magnetic resonance imaging.

OBJECTIVE: To evaluate the distribution of shoulder and elbow injuries confirmed by magnetic resonance imaging in throwing athletes.

STUDY DESIGN: Descriptive epidemiological study.

SETTING: Tertiary institution.

PARTICIPANTS: Five hundred fifty-four baseball players referred to our institute for shoulder and elbow rehabilitation.

INTERVENTIONS: All injured players except those with fractures underwent magnetic resonance imagings, which were read by a radiologist, and players were diagnosed by orthopedic surgeons based on the clinical and imaging findings.

MAIN OUTCOME MEASURES: Analysis of baseball-related injuries was performed according to the physical characteristics of each athlete and his positions on the team.

RESULTS: Junior high school players sustained a higher proportion of osteochondritis dissecans compared with high school and collegiate players. High school and collegiate players were more likely to have ulnar collateral ligament (UCL) injuries or superior labrum anterior-posterior (SLAP) lesions than junior high school players. Pitchers and outfielders were more likely to have UCL injuries than the infielders. In the junior high school group, the players with UCL injuries were taller and heavier than the players in the control group. In the high school group with UCL injuries or SLAP lesions, the players were both taller and heavier than the players in the control group.

CONCLUSIONS: These data support the conclusion that there is a significant difference in the distribution of injuries according to the player's age and position. For the age-matched comparison, taller and heavier players are more likely to be affected by UCL injury or SLAP lesion.